- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
Longitudinal lining plates for ball mill of wedgelike shape. The thin edge of each wedge underlies the thick edge of the preceding plate in the direction of revolution.
Industry:Mining
Longwall coal faces equipped for the automatic starting, stopping, and steering of power-loading machines as well as the manipulation of electric trailing cables, including air and water hoses; controlled automatic advancing of face conveyors as well as advancing and setting of roof supports. Each and all operations are correctly phased and accomplished from a remote point. With the advent of electronics and automation techniques, the prospects of manless coal mining are very promising.
Industry:Mining
Loose stone, or waste rock; loose sandy or stony barren soil; mixed shale and sandstone. Also spelled: rammell.
Industry:Mining
Loosely bound aggregate of stable molecules; e.g., dry ice, solid iodine, sulfur, paraffin, and most of the other crystalline organic solids.
Industry:Mining
Loosely twisted fiber usually of hemp or jute impregnated with tar or with a tar derivative (such as creosote or asphalt); used in caulking seams (such as the wood hulls and decks of ships) and in packing joints (in pipes, caissons, etc.).
Industry:Mining
Loss in voltage owing to the resistance of conductors conveying electricity from a power station to the consumer.
Industry:Mining
Losses of air occurring in the restricted area around the tub and caused by the increased velocity along the walls of the airway, and from the friction and turbulent effects due to the surfaces of the tub. For an empty tub, a portion of the turbulent effect is due to eddying and shock within the tub.
Industry:Mining
Low capacity, semiportable refrigeration unit of 150,000 to 500,000 Btu/h (44 to 146.5 kW) cooling capacity that is used in cooling sites of limited extent, such as an underground enginehouse or the face of a development end. The refrigerant used is nontoxic, and an electric or compressed-air drive is applied to a reciprocating compressor.
Industry:Mining
Low grade of virgin zinc containing about 98% zinc, 1.60% lead, 0.08% iron, with no limitations on cadmium or aluminum.
Industry:Mining
Low working voltage in coal mines is one of the many conditions that must be given continual attention. Loss of voltage means a proportional loss in power. Since the quantity of dc power is obtained by multiplying the number of amperes times the number of volts, it follows that for a given amount of power if the volts are lowered the amperes are increased, and the increase in amperes results in an increase in power loss in the mine circuit. Lower operating voltages result in heavier currents in the dc motor circuits, thus heating the motors, cables, and circuit wiring and causing loss in motor speed, inefficient operation, and increased maintenance cost.
Industry:Mining
